An update on the bioactivities and health benefits of two plant-derived lignans, phyllanthin and hypophyllanthin

Polyphenols are notable phytochemicals mostly found in plant-based foods, with many reported health benefits. Only limited information is available in the literature on polyphenolic lignans; hence, this review highlights the findings from an extensive open-ended search performed on many databases and search engines, using the keywords “phyllanthin” and “hypophyllanthin” inserted separately and jointly into these databases. Up to 2700 distinct articles were generated, most of which were related to plants of the Phyllanthus species. Plant extract-based articles were excluded. 468 original articles and bibliographic reviews that met the inclusion criteria were selected. Our search showed that both lignans were mostly isolated from plant sources, and some of their biological and pharmacological activities have been previously studied in in silico, in vitro and in vivo experimental models. Only a few human studies were reported, mainly in ex-vivo studies with blood samples and parasites. The antioxidant, anti-inflammatory and immunomodulatory, cardiovascular and cardioprotective, antimicrobial, antiviral, antiparasitic, neuroprotective and neuroactive, anti-diabetic, reno-protective and uricosuric, hepatoprotective, metabolic as well as anticancer effects are well-documented and described in the different sections of this review, as summarized in Table 1. No direct toxicity and side effects were reported. The health benefits identified in the reviewed articles potentially provide some rationale for further scientific research on these lignans’ toxicology, safety profiles, pharmacokinetics, and pharmacodynamics, with a view to progressing through the clinical trial phases of the drug discovery and development process.